63269-92-1Relevant academic research and scientific papers
Copper(I)-catalyzed addition of grignard reagents to in situ-derived N -sulfonyl azoalkenes: An umpolung alkylation procedure applicable to the formation of up to three contiguous quaternary centers
Hatcher, John M.,Coltart, Don M.
supporting information; experimental part, p. 4546 - 4547 (2010/06/13)
The α-alkylation of N-sulfonyl hydrazones via in situ-derived azoalkenes provides an umpolung approach to ketone α-alkylation that has considerable potential with regard to catalysis and the direct incorporation of functionality not amenable to the use of enolate chemistry. Herein, we describe the first Cu(I)-catalyzed addition of Grignard reagents to in situ-derived N-sulfonyl azoalkenes. This method is remarkable in its ability to deliver highly sterically hindered compounds that would be difficult or impossible to synthesize via traditional enolate chemistry, including those having up to three contiguous quaternary centers.
Elucidation of the catalytic mechanisms of the non-haem iron-dependent catechol dioxygenases: Synthesis of carba-analogues for hydroperoxide reaction intermediates
Winfield, Christopher J.,Al-Mahrizy, Zeyana,Gravestock, Michael,Bugg, Timothy D.H.
, p. 3277 - 3289 (2007/10/03)
The catalytic mechanisms of the non-haem iron-dependent intradiol and extradiol catechol dioxygenases are thought to involve transient hydroperoxide reaction intermediates, formed by reaction of a catechol substrate with dioxygen. The synthesis of carba-analogues of these intermediates is described in which the hydroperoxide functional group (-OOH) is replaced by a hydroxymethyl group (-CH2OH), and the cyclohexadienone skeleton simplified to a cyclohexanone. Analogues of the "proximal" hydroperoxide in which the hydroxymethyl group was positioned axially with respect to the ring were found to act as reversible competitive inhibitors (Ki 0.7-7.6 mM) for the extradiol enzyme 2,3-dihydroxyphenylpropionate 1,2-dioxygenase (MhpB) from Escherichia coli, whereas analogues in which the hydroxymethyl group was positioned equatorially showed no inhibition. In contrast, assays versus the intradiol-cleaving protocatechuate 3,4-dioxygenase from Pseudomonas sp. showed inhibition only by an analogue containing an equatorial hydroxymethyl group (IC50 9.5 mM). These data support the existence of a proximal hydroperoxide intermediate in the extradiol catechol dioxygenase mechanism, and suggest that the conformation adopted by the hydroperoxide reaction intermediate may be an important determinant in the reaction specificity of the extradiol and intradiol dioxygenases. The Royal Society of Chemistry 2000.
